1. Technical Field
The present invention relates to a process for producing expandable nut-based pellet snacks and, in particular, to a process for producing expandable pellets using an extruder. The process produces shelf stable half-products, or pellets, which can be later processed into finished snack chips. The present invention also relates to a process of pressure cooking the shelf stable half-products and other ingredients to produce a snack chip.
2. Description of Related Art
Finished snack products made with pellets typically require two steps to produce. In a first step, the ingredients, which generally include cereal products and starches, are hydrated to form an extrudable mixture. During extrusion, the ingredients are partially gelatinized creating dough, which is passed through a die to form an extrudate. The extrudate is then cut into pellets (with or without lamination) and processed through a dryer to partially dehydrate the pellets. This dehydrated pellet, or half product, can then be stored and later processed, or immediately processed in a second cooking step.
One advantage of a half-product is that it is inexpensive and easy to handle. Because half-products or pellets can be stored for relatively long periods of time before further processing, they can be centrally manufactured and shipped to several facilities in different geographical regions for a final cooking step. Further, following cooking, seasonings can be added that accommodate diverse geographical preferences.
Prior art pellet making processes have focused upon corn-based products, as illustrated by U.S. Pat. Nos. 6,224,933 and 6,242,034 and potato-based products, as illustrated by U.S. Pat. No. 6,432,463. While potato-based snack products and corn-based snack products are known, it would be desirable to have food products made with alternative compositions to make products that have different nutritional and flavor profiles. For example, many consumers are increasingly health conscious and desire healthier, naturally flavored snack food products with higher levels of protein and fiber, and lower levels of fat than many traditional corn or potato-based snack foods. After frying, corn-based products can have an oil content of more than 25% by weight and the potato-based products can have an oil content of more than 35% by weight. Further, corn-based products have a very distinctive flavor, which can result in a limited set of flavor profiles.
Nuts are considered by consumers to be a healthy food product. Peanuts and other types of nuts are preferred snack items because they have a high protein content. Many nuts also have high fiber content, which has been attributed to reducing a person's risk of certain cancers, diabetes, digestive disorders, and heart diseases. Fiber may also help people control obesity, because insoluble fiber is not digested and passes through the digestive system virtually in tact, providing bulk but very few calories. Studies have also shown that people who consume nuts on a regular basis are less likely to suffer from coronary heart disease and can lower their LDL cholesterol levels, probably due to the fatty acid profile of nuts.
No prior art process has been successful in creating an extruded half-product with a high content of nuts, nor has the prior art been able to produce desirable chip-like snacks from such half-products. Accordingly, a need exists for a process for making expandable nut-based pellets which have pellet attributes including significant storability, and using the nut-based pellets to make chip like snacks with improved shape, texture, and flavor while being easily manufactured. Further, the expandable pellet and snack chip should, in one embodiment, provide the consumer with a reduced fat, and/or higher protein and fiber snack food while providing desirable nut flavor profiles.